The present invention relates to a solid-state information display apparatus for an automotive vehicle for indicating to the vehicle operator the status of parameters which altogether represent the condition of the vehicle being then monitored.
Automobile vehicles are presently provided with a solid-state information display apparatus for indicating to the vehicle operator the status of the some or all of engine oil pressure, coolant temperature, engine speed, vehicle speed, travelling distance, mileage per gallon of fuel and other parameters of a similar nature. In general, the conventional display apparatus comprises an instrument panel positioned in front of a driver's seat inside the body of the vehicle and includes solid-state gauges displaying those parameters which altogether represent the condition of the vehicle being then monitored. Those solid-state gauges are each constituted by one or more arrays of either electro-luminescent elements, such as light emitting diodes, incandescent descent lamps or fluorescent luminescence tubes or liquid crystal display cells in combination with one or more illuminating lamps, which arrays are arranged in a predetermined pattern including one or both of numerical representations and graphic representations.
Since the conventional display apparatus is generally so designed that all of those solid-state gauges are enabled at least when and after the automobile engine has been operated, the vehicle operator tends to be dazzled by excessive light emitted from those gauges, with his or her eyes getting readily tired. In addition to this inconvenience, the fact that all of the solid-state gauges are enabled requires a relatively large amount of electrical power to be consumed while the electrical power available in the vehicle is limited.
Considering a general notion that all of the parameters need not be always displayed at all times except for the vehicle speed which is required to be displayed at all times during the use of the vehicle, i.e., the operation of the engine and/or the running of the vehicle, in view of local traffic regulations, it may be contemplated to divide the parameters to be displayed into two group, one group being displayed at all times during the use of the vehicle and the other group being displayable manually upon demand, i.e., at the vehicle operator's will, and automatically in case of an emergency, i.e., when an out-of-limits condition occurs. This contemplation has been embodied in, for example, U.S. Pat. Nos. 3,866,166 and 4,031,363.
According to these U.S. patents, the system is such that, while the first mentioned group of the parameter or parameters are displayed through its or their own solid-state displays, the second mentioned group of the parameter or parameters are displayed through a single solid-state display on a selective basis. With the system of any one of these U.S. patents, not only can some or all of the parameters of the second-mentioned group not be displayed simultaneously when the vehicle operator so desires, but also an inconvenience will arise when an out-of-limits condition occurs in connection with two or more parameters of the second mentioned group.